Al Qaeda leader Ayman al-Zawahri has warned the United States of the “gravest consequences” if Boston marathon bomber Dzhokhar Tsarnaev or any other Muslim prisoner is executed. Tsarnaev, named in a new online video message from Zawahri, was sentenced last year to death by lethal injection for the 2013 bomb attack, which killed three people … Continue reading Al Qaeda leader warns of ‘gravest consequences’ if Boston bomber executed